title: A 10-year retrospective cohort study on the risk factors for peritoneal dialysis-related peritonitis: a single-center study at Tokai University Hospital.
abstract: BACKGROUND
  Common outcomes of peritoneal dialysis (PD)-related peritonitis include catheter removal and transition to hemodialysis (HD). According to recent data, the incidence of PD-related peritonitis in Japan is not low, and peritonitis is the most common cause of withdrawal from PD. Against this backdrop, the purpose of this study is to determine the incidence of PD-related peritonitis at the Outpatient Nephrology Clinic of Tokai University Hospital (hereafter "the Clinic") and to examine causative bacteria and the risk factors related to the development of peritonitis.
  
  
  METHODS
  We investigated all PD-related peritonitis episodes of 192 PD patients who visited the Clinic during the period from April 1, 2001 to March 31, 2011 and established the incidence of PD-related peritonitis, along with culture-negative peritonitis rates. Regarding the risk factors that are associated with the development of peritonitis, we examined patient backgrounds, whether an automated peritoneal dialysis (APD) device was used, and which type of connection system was employed.
  
  
  RESULTS
  The incidence of peritonitis was one episode per 64.5 patient-months, and the culture-negative peritonitis rate was 16.4 %. Of the cultured bacterial isolates 71.3 % were Gram-positive cocci, including 25.0 % of coagulase-negative staphylococci, 13.2 % of methicillin-susceptible Staphylococcus aureus (MSSA), and 6.6 % of methicillin-resistant Staphylococcus aureus (MRSA). Gram-negative rods were 19.1 %. Risk factors associated with the development of peritonitis included age at the start of PD [odds ratio 1.042, 95 % confidence interval (CI) 1.016-1.069, p value = 0.001], diabetes mellitus nephropathy (DMN) (odds ratio 22.003, 95 % CI 2.101-230.452, p value = 0.010), and the use of a sterile tubing welder device (STWD) (odds ratio 2.399, 95 % CI 1.043-5.521, p value = 0.040).
  
  
  CONCLUSIONS
  Regarding the situation of peritonitis at a single center during the 10-year period of this study, risk factors associated with the development of peritonitis included age at the start of PD, DMN, and the use of an STWD.
authors.affiliation: Division of General Internal Medicine, Department of Internal Medicine, Tokai University School of Medicine, 143, Shimokasuya, Isehara, Kanagawa, 259-1193, Japan, nishina@is.icc.u-tokai.ac.jp.
authors.forename: Makoto
authors.initials: M
authors.lastname: Nishina
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Yanagi
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Kakuta
authors.forename: Masayuki
authors.initials: M
authors.lastname: Endoh
authors.forename: Masafumi
authors.initials: M
authors.lastname: Fukagawa
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takagi
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001424:Bacterial Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D003928:Diabetic Nephropathies / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy*; D004867:Equipment Design; D005260:Female; D006785:Hospitals, University; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D010530:Peritoneal Dialysis / Q000009:adverse effects* / Q000295:instrumentation; D010538:Peritonitis / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome